Method and apparatus for sending uplink control information for multi-radio access technology operation

ABSTRACT

A method and apparatus for sending uplink control information (UCI) by a multi-mode wireless transmit/receive unit (WTRU) capable of operating on multiple component carriers of a plurality of radio access technologies (RATs) for multi-RAT operation are disclosed. The multi-mode WTRU may generate UCI pertaining to a first RAT and send at least part of the UCI via a feedback channel on a component carrier of a second RAT. The first RAT may be Long Term Evolution (LTE) and the second RAT may be High Speed Packet Access (HSPA), or vice versa. The UCI of the RATs may be multiplexed onto a carrier of any one of the RATs. The UCI bits for a pair of, or multiple, serving cells may be jointly encoded.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. provisional application No.61/450,039 filed Mar. 7, 2011, the contents of which is herebyincorporated by reference herein.

BACKGROUND

The demand for improved network coverage and increased capacity andbandwidth for both voice and data services in wireless communicationsystems has led to continuous developments of radio access technologies(RATs) including, but not limited to, Global System for Mobilecommunication (GSM), Wideband Channel Division Multiple Access (WCDMA),High Speed Packet Access (HSPA) including High Speed Downlink PacketAccess (HSDPA) and High Speed Uplink Packet Access (HSUPA) with theirrespective multicarrier counterparts, Long Term Evolution (LTE)including support for carrier aggregation in Release 10 (R10), IEEE802.11b/a/g/n, IEEE 802.16a/e, IEEE 802.20, cdma20001x, cdma2000 EV-DO.

The Third Generation Partnership Project (3GPP) WCDMA Release 8 (R8)introduced support for simultaneous use of two HSDPA downlink carriers(2C-HSDPA) to improve bandwidth usage with frequency diversity andresource pooling. 3GPP Release 9 (R9) introduced support formultiple-input multiple-output (MIMO) to the multicarrier downlinkWCDMA. 3GPP R9 also introduced support for two HSUPA uplink carriers.3GPP R10 introduced support for up to 4 downlink carriers (4C-HSDPA).This may be increased to up to 8 downlink carriers (8C-HSDPA) in 3GPPRelease 11 (R11).

3GPP LTE R10 introduced support for simulaneous transmission and/orreception using the radio resources of a plurality of component carriersbetween a network node (i.e., evolved NodeB (eNB)) and a mobile terminal(i.e., wireless transmit/receive unit (WTRU)) within the sametransmission interval. R10 HSPA with MIMO offers downlink peak datarates of 42 Mbps, while R10 multicarrier HSPA may further increase thepeak rate by introducing support for up to four downlink componentcarriers. LTE R8/9 offers up to 100 Mbps in the single carrier downlink,while LTE R10 with (intra-RAT) carrier aggregation may further increasethe peak rate by combining transmission resources of up to 5 componentcarriers.

Spectrum is a costly resource and not all frequency bands may beavailable to all operators. While many operators may offer support forboth HSPA and LTE services, carrier aggregation may be limited to 2-3component carriers per RAT for a given operator. In addition, legacydeployments may be maintained for a foreseeable future while LTE isbeing deployed. This may lead to a situation where operators may seeperiods of underutilization of radio resources/spectrum and capacity inone of their RATs.

SUMMARY

A method and apparatus for sending uplink control information (UCI) by amulti-mode WTRU capable of operating on multiple component carriers of aplurality of RATs for multi-RAT operation are disclosed. The multi-modeWTRU may generate UCI pertaining to a first RAT and send at least partof the UCI via a feedback channel on a component carrier of a secondRAT. The first RAT may be LTE and the second RAT may be HSPA, or viceversa. The UCI of the RATs may be multiplexed onto a carrier of any oneof the RATs. The UCI bits for a pair of, or multiple, serving cells maybe jointly encoded.

BRIEF DESCRIPTION OF THE DRAWINGS

A more detailed understanding may be had from the following description,given by way of example in conjunction with the accompanying drawingswherein:

FIG. 1A is a system diagram of an example communications system in whichone or more disclosed embodiments may be implemented;

FIG. 1B is a system diagram of an example wireless transmit/receive unit(WTRU) that may be used within the communications system illustrated inFIG. 1A;

FIG. 1C is a system diagram of an example UMTS radio access network andan example UMTS core network that may be used within the communicationssystem illustrated in FIG. 1A;

FIG. 1D is a system diagram of an example LTE RAN and an example LTEcore network that may be used within the communications systemillustrated in FIG. 1A;

FIG. 2 is a flow diagram of an example process for multiplexing the LTEUCI and the HSPA UCI in accordance with one embodiment; and

FIGS. 3 and 4 show frame structures of HSPA and LTE, respectively.

DETAILED DESCRIPTION

FIG. 1A is a diagram of an example communications system 100 in whichone or more disclosed embodiments may be implemented. The communicationssystem 100 may be a multiple access system that provides content, suchas voice, data, video, messaging, broadcast, etc., to multiple wirelessusers. The communications system 100 may enable multiple wireless usersto access such content through the sharing of system resources,including wireless bandwidth. For example, the communications systems100 may employ one or more channel access methods, such as code divisionmultiple access (CDMA), time division multiple access (TDMA), frequencydivision multiple access (FDMA), orthogonal FDMA (OFDMA), single-carrierFDMA (SC-FDMA), and the like.

As shown in FIG. 1A, the communications system 100 may include wirelesstransmit/receive units (WTRUs) 102 a, 102 b, 102 c, 102 d, a radioaccess network (RAN) 104, a core network 106, a public switchedtelephone network (PSTN) 108, the Internet 110, and other networks 112,though it will be appreciated that the disclosed embodiments contemplateany number of WTRUs, base stations, networks, and/or network elements.Each of the WTRUs 102 a, 102 b, 102 c, 102 d may be any type of deviceconfigured to operate and/or communicate in a wireless environment. Byway of example, the WTRUs 102 a, 102 b, 102 c, 102 d may be configuredto transmit and/or receive wireless signals and may include userequipment (UE), a mobile station, a fixed or mobile subscriber unit, apager, a cellular telephone, a personal digital assistant (PDA), asmartphone, a laptop, a netbook, a personal computer, a wireless sensor,consumer electronics, and the like.

The communications systems 100 may also include a base station 114 a anda base station 114 b. Each of the base stations 114 a, 114 b may be anytype of device configured to wirelessly interface with at least one ofthe WTRUs 102 a, 102 b, 102 c, 102 d to facilitate access to one or morecommunication networks, such as the core network 106, the Internet 110,and/or the networks 112. By way of example, the base stations 114 a, 114b may be a base transceiver station (BTS), a Node-B, an eNode B, a HomeNode B, a Home eNode B, a site controller, an access point (AP), awireless router, and the like. While the base stations 114 a, 114 b areeach depicted as a single element, it will be appreciated that the basestations 114 a, 114 b may include any number of interconnected basestations and/or network elements.

The base station 114 a may be part of the RAN 104, which may alsoinclude other base stations and/or network elements (not shown), such asa base station controller (BSC), a radio network controller (RNC), relaynodes, etc. The base station 114 a and/or the base station 114 b may beconfigured to transmit and/or receive wireless signals within aparticular geographic region, which may be referred to as a cell (notshown). The cell may further be divided into cell sectors. For example,the cell associated with the base station 114 a may be divided intothree sectors. Thus, in one embodiment, the base station 114 a mayinclude three transceivers, i.e., one for each sector of the cell. Inanother embodiment, the base station 114 a may employ multiple-inputmultiple output (MIMO) technology and, therefore, may utilize multipletransceivers for each sector of the cell.

The base stations 114 a, 114 b may communicate with one or more of theWTRUs 102 a, 102 b, 102 c, 102 d over an air interface 116, which may beany suitable wireless communication link (e.g., radio frequency (RF),microwave, infrared (IR), ultraviolet (UV), visible light, etc.). Theair interface 116 may be established using any suitable radio accesstechnology (RAT).

More specifically, as noted above, the communications system 100 may bea multiple access system and may employ one or more channel accessschemes, such as CDMA, TDMA, FDMA, OFDMA, SC-FDMA, and the like. Forexample, the base station 114 a in the RAN 104 and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Universal MobileTelecommunications System (UMTS) Terrestrial Radio Access (UTRA), whichmay establish the air interface 116 using wideband CDMA (WCDMA). WCDMAmay include communication protocols such as High-Speed Packet Access(HSPA) and/or Evolved HSPA (HSPA+). HSPA may include High-Speed DownlinkPacket Access (HSDPA) and/or High-Speed Uplink Packet Access (HSUPA).

In another embodiment, the base station 114 a and the WTRUs 102 a, 102b, 102 c may implement a radio technology such as Evolved UMTSTerrestrial Radio Access (E-UTRA), which may establish the air interface116 using Long Term Evolution (LTE) and/or LTE-Advanced (LTE-A).

In other embodiments, the base station 114 a and the WTRUs 102 a, 102 b,102 c may implement radio technologies such as IEEE 802.16 (i.e.,Worldwide Interoperability for Microwave Access (WiMAX)), CDMA2000,CDMA2000 1X, CDMA2000 EV-DO, Interim Standard 2000 (IS-2000), InterimStandard 95 (IS-95), Interim Standard 856 (IS-856), Global System forMobile communications (GSM), Enhanced Data rates for GSM Evolution(EDGE), GSM EDGE (GERAN), and the like.

The base station 114 b in FIG. 1A may be a wireless router, Home Node B,Home eNode B, or access point, for example, and may utilize any suitableRAT for facilitating wireless connectivity in a localized area, such asa place of business, a home, a vehicle, a campus, and the like. In oneembodiment, the base station 114 b and the WTRUs 102 c, 102 d mayimplement a radio technology such as IEEE 802.11 to establish a wirelesslocal area network (WLAN). In another embodiment, the base station 114 band the WTRUs 102 c, 102 d may implement a radio technology such as IEEE802.15 to establish a wireless personal area network (WPAN). In yetanother embodiment, the base station 114 b and the WTRUs 102 c, 102 dmay utilize a cellular-based RAT (e.g., WCDMA, CDMA2000, GSM, LTE,LTE-A, etc.) to establish a picocell or femtocell. As shown in FIG. 1A,the base station 114 b may have a direct connection to the Internet 110.Thus, the base station 114 b may not be required to access the Internet110 via the core network 106.

The RAN 104 may be in communication with the core network 106, which maybe any type of network configured to provide voice, data, applications,and/or voice over internet protocol (VoIP) services to one or more ofthe WTRUs 102 a, 102 b, 102 c, 102 d. For example, the core network 106may provide call control, billing services, mobile location-basedservices, pre-paid calling, Internet connectivity, video distribution,etc., and/or perform high-level security functions, such as userauthentication. Although not shown in FIG. 1A, it will be appreciatedthat the RAN 104 and/or the core network 106 may be in direct orindirect communication with other RANs that employ the same RAT as theRAN 104 or a different RAT. For example, in addition to being connectedto the RAN 104, which may be utilizing an E-UTRA radio technology, thecore network 106 may also be in communication with another RAN (notshown) employing a GSM radio technology.

The core network 106 may also serve as a gateway for the WTRUs 102 a,102 b, 102 c, 102 d to access the PSTN 108, the Internet 110, and/orother networks 112. The PSTN 108 may include circuit-switched telephonenetworks that provide plain old telephone service (POTS). The Internet110 may include a global system of interconnected computer networks anddevices that use common communication protocols, such as thetransmission control protocol (TCP), user datagram protocol (UDP) andthe internet protocol (IP) in the TCP/IP internet protocol suite. Thenetworks 112 may include wired or wireless communications networks ownedand/or operated by other service providers. For example, the networks112 may include another core network connected to one or more RANs,which may employ the same RAT as the RAN 104 or a different RAT.

Some or all of the WTRUs 102 a, 102 b, 102 c, 102 d in thecommunications system 100 may include multi-mode capabilities, i.e., theWTRUs 102 a, 102 b, 102 c, 102 d may include multiple transceivers forcommunicating with different wireless networks over different wirelesslinks. For example, the WTRU 102 c shown in FIG. 1A may be configured tocommunicate with the base station 114 a, which may employ acellular-based radio technology, and with the base station 114 b, whichmay employ an IEEE 802 radio technology.

FIG. 1B is a system diagram of an example WTRU 102. As shown in FIG. 1B,the WTRU 102 may include a processor 118, a transceiver 120, atransmit/receive element 122, a speaker/microphone 124, a keypad 126, adisplay/touchpad 128, non-removable memory 106, removable memory 132, apower source 134, a global positioning system (GPS) chipset 136, andother peripherals 138. It will be appreciated that the WTRU 102 mayinclude any sub-combination of the foregoing elements while remainingconsistent with an embodiment.

The processor 118 may be a general purpose processor, a special purposeprocessor, a conventional processor, a digital signal processor (DSP), aplurality of microprocessors, one or more microprocessors in associationwith a DSP core, a controller, a microcontroller, Application SpecificIntegrated Circuits (ASICs), Field Programmable Gate Array (FPGAs)circuits, any other type of integrated circuit (IC), a state machine,and the like. The processor 118 may perform signal coding, dataprocessing, power control, input/output processing, and/or any otherfunctionality that enables the WTRU 102 to operate in a wirelessenvironment. The processor 118 may be coupled to the transceiver 120,which may be coupled to the transmit/receive element 122. While FIG. 1Bdepicts the processor 118 and the transceiver 120 as separatecomponents, it will be appreciated that the processor 118 and thetransceiver 120 may be integrated together in an electronic package orchip.

The transmit/receive element 122 may be configured to transmit signalsto, or receive signals from, a base station (e.g., the base station 114a) over the air interface 116. For example, in one embodiment, thetransmit/receive element 122 may be an antenna configured to transmitand/or receive RF signals. In another embodiment, the transmit/receiveelement 122 may be an emitter/detector configured to transmit and/orreceive IR, UV, or visible light signals, for example. In yet anotherembodiment, the transmit/receive element 122 may be configured totransmit and receive both RF and light signals. It will be appreciatedthat the transmit/receive element 122 may be configured to transmitand/or receive any combination of wireless signals.

In addition, although the transmit/receive element 122 is depicted inFIG. 1B as a single element, the WTRU 102 may include any number oftransmit/receive elements 122. More specifically, the WTRU 102 mayemploy MIMO technology. Thus, in one embodiment, the WTRU 102 mayinclude two or more transmit/receive elements 122 (e.g., multipleantennas) for transmitting and receiving wireless signals over the airinterface 116.

The transceiver 120 may be configured to modulate the signals that areto be transmitted by the transmit/receive element 122 and to demodulatethe signals that are received by the transmit/receive element 122. Asnoted above, the WTRU 102 may have multi-mode capabilities. Thus, thetransceiver 120 may include multiple transceivers for enabling the WTRU102 to communicate via multiple RATs, such as UTRA and IEEE 802.11, forexample.

The processor 118 of the WTRU 102 may be coupled to, and may receiveuser input data from, the speaker/microphone 124, the keypad 126, and/orthe display/touchpad 128 (e.g., a liquid crystal display (LCD) displayunit or organic light-emitting diode (OLED) display unit). The processor118 may also output user data to the speaker/microphone 124, the keypad126, and/or the display/touchpad 128. In addition, the processor 118 mayaccess information from, and store data in, any type of suitable memory,such as the non-removable memory 106 and/or the removable memory 132.The non-removable memory 106 may include random-access memory (RAM),read-only memory (ROM), a hard disk, or any other type of memory storagedevice. The removable memory 132 may include a subscriber identitymodule (SIM) card, a memory stick, a secure digital (SD) memory card,and the like. In other embodiments, the processor 118 may accessinformation from, and store data in, memory that is not physicallylocated on the WTRU 102, such as on a server or a home computer (notshown).

The processor 118 may receive power from the power source 134, and maybe configured to distribute and/or control the power to the othercomponents in the WTRU 102. The power source 134 may be any suitabledevice for powering the WTRU 102. For example, the power source 134 mayinclude one or more dry cell batteries (e.g., nickel-cadmium (NiCd),nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion),etc.), solar cells, fuel cells, and the like.

The processor 118 may also be coupled to the GPS chipset 136, which maybe configured to provide location information (e.g., longitude andlatitude) regarding the current location of the WTRU 102. In additionto, or in lieu of, the information from the GPS chipset 136, the WTRU102 may receive location information over the air interface 116 from abase station (e.g., base stations 114 a, 114 b) and/or determine itslocation based on the timing of the signals being received from two ormore nearby base stations. It will be appreciated that the WTRU 102 mayacquire location information by way of any suitablelocation-determination method while remaining consistent with anembodiment.

The processor 118 may further be coupled to other peripherals 138, whichmay include one or more software and/or hardware modules that provideadditional features, functionality and/or wired or wirelessconnectivity. For example, the peripherals 138 may include anaccelerometer, an e-compass, a satellite transceiver, a digital camera(for photographs or video), a universal serial bus (USB) port, avibration device, a television transceiver, a hands free headset, aBluetooth® module, a frequency modulated (FM) radio unit, a digitalmusic player, a media player, a video game player module, an Internetbrowser, and the like.

FIG. 1C is a system diagram of the RAN 104 and the core network 106according to an embodiment. As noted above, the RAN 104 may employ aUTRA radio technology to communicate with the WTRUs 102 a, 102 b, 102 cover the air interface 116. The RAN 104 may also be in communicationwith the core network 106. As shown in FIG. 1C, the RAN 104 may includeNode-Bs 140 a, 140 b, 140 c, which may each include one or moretransceivers for communicating with the WTRUs 102 a, 102 b, 102 c overthe air interface 116. The Node-Bs 140 a, 140 b, 140 c may each beassociated with a particular cell (not shown) within the RAN 104. TheRAN 104 may also include RNCs 142 a, 142 b. It will be appreciated thatthe RAN 104 may include any number of Node-Bs and RNCs while remainingconsistent with an embodiment.

As shown in FIG. 1C, the Node-Bs 140 a, 140 b may be in communicationwith the RNC 142 a. Additionally, the Node-B 140 c may be incommunication with the RNC142 b. The Node-Bs 140 a, 140 b, 140 c maycommunicate with the respective RNCs 142 a, 142 b via an Iub interface.The RNCs 142 a, 142 b may be in communication with one another via anIur interface. Each of the RNCs 142 a, 142 b may be configured tocontrol the respective Node-Bs 140 a, 140 b, 140 c to which it isconnected. In addition, each of the RNCs 142 a, 142 b may be configuredto carry out or support other functionality, such as outer loop powercontrol, load control, admission control, packet scheduling, handovercontrol, macrodiversity, security functions, data encryption, and thelike.

The core network 106 shown in FIG. 1C may include a media gateway (MGW)144, a mobile switching center (MSC) 146, a serving GPRS support node(SGSN) 148, and/or a gateway GPRS support node (GGSN) 150. While each ofthe foregoing elements are depicted as part of the core network 106, itwill be appreciated that any one of these elements may be owned and/oroperated by an entity other than the core network operator.

The RNC 142 a in the RAN 104 may be connected to the MSC 146 in the corenetwork 106 via an IuCS interface. The MSC 146 may be connected to theMGW 144. The MSC 146 and the MGW 144 may provide the WTRUs 102 a, 102 b,102 c with access to circuit-switched networks, such as the PSTN 108, tofacilitate communications between the WTRUs 102 a, 102 b, 102 c andtraditional land-line communications devices.

The RNC 142 a in the RAN 104 may also be connected to the SGSN 148 inthe core network 106 via an IuPS interface. The SGSN 148 may beconnected to the GGSN 150. The SGSN 148 and the GGSN 150 may provide theWTRUs 102 a, 102 b, 102 c with access to packet-switched networks, suchas the Internet 110, to facilitate communications between and the WTRUs102 a, 102 b, 102 c and IP-enabled devices.

As noted above, the core network 106 may also be connected to thenetworks 112, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

FIG. 1D is a system diagram of an example LTE RAN 154 and an example LTEcore network 156 that may be used within the communications systemillustrated in FIG. 1A. The RAN 154 employs an E-UTRA radio technologyto communicate with the WTRUs 152 a, 152 b, 152 c over the air interface166. The RAN 154 may also be in communication with the core network 156.

The RAN 154 may include eNode-Bs 190 a, 190 b, 190 c, though it will beappreciated that the RAN 154 may include any number of eNode-Bs whileremaining consistent with an embodiment. The eNode-Bs 190 a, 190 b, 190c may each include one or more transceivers for communicating with theWTRUs 152 a, 152 b, 152 c over the air interface 166. In one embodiment,the eNode-Bs 190 a, 190 b, 190 c may implement MIMO technology. Thus,the eNode-B 190 a, for example, may use multiple antennas to transmitwireless signals to, and receive wireless signals from, the WTRU 152 a.

Each of the eNode-Bs 190 a, 190 b, 190 c may be associated with aparticular cell (not shown) and may be configured to handle radioresource management decisions, handover decisions, scheduling of usersin the uplink and/or downlink, and the like. As shown in FIG. 1D, theeNode-Bs 190 a, 190 b, 190 c may communicate with one another over an X2interface.

The core network 156 shown in FIG. 1D may include a mobility managementgateway (MME) 192, a serving gateway 194, and a packet data network(PDN) gateway 196. While each of the foregoing elements are depicted aspart of the core network 156, it will be appreciated that any one ofthese elements may be owned and/or operated by an entity other than thecore network operator.

The MME 192 may be connected to each of the eNode-Bs 192 a, 192 b, 192 cin the RAN 154 via an S1 interface and may serve as a control node. Forexample, the MME 192 may be responsible for authenticating users of theWTRUs 152 a, 152 b, 152 c, bearer activation/deactivation, selecting aparticular serving gateway during an initial attach of the WTRUs 152 a,152 b, 152 c, and the like. The MME 192 may also provide a control planefunction for switching between the RAN 154 and other RANs (not shown)that employ other radio technologies, such as GSM or WCDMA.

The serving gateway 194 may be connected to each of the eNode Bs 190 a,190 b, 190 c in the RAN 154 via the S1 interface. The serving gateway194 may generally route and forward user data packets to/from the WTRUs152 a, 152 b, 152 c. The serving gateway 194 may also perform otherfunctions, such as anchoring user planes during inter-eNode B handovers,triggering paging when downlink data is available for the WTRUs 152 a,152 b, 152 c, managing and storing contexts of the WTRUs 152 a, 152 b,152 c, and the like.

The serving gateway 194 may also be connected to the PDN gateway 196,which may provide the WTRUs 152 a, 152 b, 152 c with access topacket-switched networks, such as the Internet 160, to facilitatecommunications between the WTRUs 152 a, 152 b, 152 c and IP-enableddevices.

The core network 156 may facilitate communications with other networks.For example, the core network 156 may provide the WTRUs 152 a, 152 b,152 c with access to circuit-switched networks, such as the PSTN 158, tofacilitate communications between the WTRUs 152 a, 152 b, 152 c andtraditional land-line communications devices. For example, the corenetwork 156 may include, or may communicate with, an IP gateway (e.g.,an IP multimedia subsystem (IMS) server) that serves as an interfacebetween the core network 156 and the PSTN 158. In addition, the corenetwork 156 may provide the WTRUs 152 a, 152 b, 152 c with access to thenetworks 162, which may include other wired or wireless networks thatare owned and/or operated by other service providers.

When referred to hereafter, the term “component carrier (CC)” means,without loss of generality, a frequency on which a WTRU operates. Forexample, a WTRU may receive transmissions on a downlink (DL) CC, whichmay comprise a plurality of DL physical channels, and the WTRU mayperform transmissions on an uplink (UL) CC, which may comprise aplurality of UL physical channels. Hereafter, the terms “componentcarrier,” “frequency,” and “carrier” will be used interchangeably.Hereafter, the terms “HARQ A/N,” “HARQ ACK/NACK,” and “HARQ-ACK” will beused interchangeably.

The LTE downlink physical channels include, but are not limited to, aPhysical Control Format Indicator Channel (PCFICH), a Physical HybridARQ Indicator Channel (PHICH), a Physical Data Control Channel (PDCCH),a Physical Multicast data Channel (PMCH), and a Physical Data SharedChannel (PDSCH). On the PCFICH, the WTRU receives control dataindicating the size of the control region of the DL CC. On the PHICH,the WTRU receives control data indicating HARQ ACK/NACK feedback for aprevious uplink transmission. On the PDCCH, the WTRU receives downlinkcontrol information (DCI) messages, for example, used for the purpose ofscheduling of downlink and uplink resources. On the PDSCH, the WTRUreceives user and/or control data.

The LTE uplink physical channels include, but are not limited to, aPhysical Uplink Control Channel (PUCCH), and a Physical Uplink SharedChannel (PUSCH). On the PUSCH, the WTRU transmits user and/or controldata. On the PUCCH, and in some case on the PUSCH, the WTRU transmitsuplink control information (such as channel state information (CSI)including channel quality indicator (CQI), precoding matrix indicator(PMI), rank indication (RI), or scheduling request (SR), and/or HARQACK/NACK feedback). On an UL CC, the WTRU may also be allocateddedicated resources for transmission of Sounding and Reference Signals(SRS).

For HSDPA, a shared channel, (i.e., the High-Speed Downlink SharedChannel (HS-DSCH)), is used for downlink transmission. The HS-DSCH is atransport channel on which the WTRU receives user data and/or controlsignaling from logical channels such as a Dedicated Transport Channel(DTCH), a Dedicated Control Channel (DCCH), a Common Control Channel(CCCH), or a Broadcast Control Channel (BCCH). The WTRU receives theHS-DSCH on the High-Speed Physical Downlink Shared Channel (HS-PDSCH).The WTRU receives on the High-Speed Shared Control Channel (HS-SCCH)downlink control signaling for scheduling the HS-PDSCH transmissions,(e.g., a transport format including a channelization code, a modulationscheme, and a transport block size), as well as other types of controlsignaling, (e.g., discontinuous reception (DRX)/discontinuoustransmission (DTX) activation/deactivation and/oractivation/deactivation commands for additional HSPA cells). The WTRUtransmits uplink feedback control information related to the HS-PDSCHtransmissions and/or HS-SCCH orders on the High-Speed Dedicated PhysicalControl Channel (HS-DPCCH). The feedback includes HARQ feedback, CQI,and precoding control indication (PCI) if the WTRU is configured forMIMO operation. Power control commands may be received by the WTRU on adedicated physical channel (DPCH) or a fractional DPCH (F-DPCH).

For HSUPA, an Enhanced Dedicated Channel (E-DCH) is used. The E-DCH ismapped on an E-DCH Dedicated Physical Data Channel (E-DPDCH). There maybe zero, one, or more E-DPDCH(s) on each radio link. The WTRU transmitscontrol information associated with the E-DCH on an E-DCH DedicatedPhysical Control Channel (E-DPCCH). There is at most one E-DPCCH on eachradio link. The dedicated physical downlink channels needed for uplinktransmissions are the F-DPCH, the E-DCH Relative Grant Channel (E-RGCH),the E-DCH Absolute Grant Channel (E-AGCH), and the E-DCH HARQ IndicatorChannel (E-HICH). The WTRU receives power control commands on a DPCH oron an F-DPCH. The WTRU receives uplink relative grants from the servingand non-serving radio links over the associated E-RGCH configured byhigher layer signaling for each serving and non-serving radio link. TheWTRU receives absolute grants for E-DCH from the serving E-DCH cell onthe E-AGCH configured by higher layer signaling. The WTRU receives HARQA/N feedback on the E-HICH.

A cell may comprise a DL CC which may be linked to an UL CC. The DLCC-UL CC association may be based on the system information (SI) that isprovided to the WTRU via broadcasting on the DL CC or via dedicatedconfiguration signaling from the network. For example, when broadcastedon the DL CC, the WTRU may receive information regarding the uplinkfrequency and bandwidth of the linked UL CC as part of the systeminformation element (e.g., when in RRC IDLE for LTE, or when inidle/CELL FACH for WCDMA, i.e. when the WTRU does not have a radioresource connection to the network).

When referred to hereafter, the term “primary cell” (PCell) means,without loss of generality, the cell operating on the primary frequencyin which the WTRU may perform initial access to the system (e.g., thecell in which the WTRU may either perform the initial connectionestablishment procedure or the connection re-establishment procedure),or the cell indicated as the primary cell in the handover procedure. ThePCell may correspond to a frequency indicated as part of the radioresource connection configuration procedure. Some functions may only besupported on the PCell. For example, the UL CC of the PCell maycorrespond to the CC whose physical uplink control channel resources areconfigured to carry the HARQ ACK/NACK feedback for a given WTRU. Forexample, in LTE, the WTRU uses the PCell to derive the parameters forthe security functions and for upper layer system information such asnon-access stratum (NAS) mobility information. Other functions that maybe supported on the PCell DL include system information acquisition andchange monitoring procedures on the BCCH, and paging. In terms ofterminology, the primary serving cell in WCDMA may be similar as thePCell of LTE.

When referred to hereafter, the term “secondary cell” (SCell) means,without loss of generality, the cell operating on a secondary frequencywhich may be configured once a radio resource control connection isestablished and which may be used to provide additional radio resources.System information relevant for operation in the concerned SCell may beprovided using dedicated signaling when the SCell is added to the WTRU'sconfiguration. Although the parameters may have different values thanthose broadcasted on the downlink of the concerned SCell using thesystem information signaling, this information is hereafter referred toas SI of the concerned SCell regardless of the method used by the WTRUto acquire this information. For example, in terms of terminology, thesecondary serving cell in WCDMA may be similar to the SCell of LTE.

When referred to hereafter, the terms “PCell DL” and “PCell UL”correspond to, without loss of generality, the DL CC and the UL CC ofthe PCell, respectively. Similarly, the terms “SCell DL” and “SCell UL”correspond to the DL CC and the UL CC of an SCell, respectively.

When referred to hereafter, the term “serving cell” includes, withoutloss of generality, a primary cell (e.g., a PCell) or a secondary cell(e.g., a SCell). More specifically, for a WTRU that is not configuredwith any SCell or that does not support operation on multiple componentcarriers (i.e., carrier aggregation), there is one serving cellcomprising the PCell. For a WTRU that is configured with at least oneSCell, the term “serving cells” includes the set of one or more cellscomprising the PCell and all configured SCell(s).

When a WTRU is configured with at least one SCell, there may be onePCell DL and one PCell UL and, for each configured SCell, there may beone SCell DL and one SCell UL (if configured).

When referred to hereafter, the term “multi-mode WTRU” includes anymobile terminal supporting a plurality of RATs such as, but not limitedto, any combination of GSM, WCDMA, HSPA, HSDPA, HSUPA, LTE, IEEE802.11b/a/g/n, 802.16a/e, 802.20, cdma20001x, cdma2000 EV-DO. It shouldbe noted that the embodiments described in greater detail hereafter maybe explained with reference to HSPA and LTE as an example, but theembodiments may be extended to any combination of the RATs.

When referred to hereafter, the terms “primary RAT” and “anchor RAT”include the RAT for which at least one serving cell is configured as aprimary cell from which at least one of the following functions issupported: the RRC connection is established and connected (in case asingle RRC connection is used), security parameters are derived (in casea single security context is used), uplink resources are used totransmit uplink control information (UCI) (in case UCI is transmitted ona serving cell of a first RAT), and/or at least one serving cell isconfigured with uplink resources (in case uplink resources areconfigured in a first RAT). The primary RAT or the anchor RAT may bereferred to as the “first RAT.”

When referred to hereafter, the terms “secondary RAT” and “non-anchorRAT” include the RAT for which none of the configured serving cell(s) isfor the primary RAT of the WTRU's configuration.

When referred to hereafter, the term “multi-RAT operation” includes anoperation of the multi-mode WTRU that is simultaneously configured foroperation with at least one component carrier, either a DL CC or an ULCC, on each of a plurality of RATs. The operation on different componentcarriers may occur either simultaneously or near-simultaneously in time.The operation on different RATs may be performed sequentially, includingon the same component carrier.

A multi-mode WTRU supports simultaneous (or near-simultaneous) operationon multiple component carriers of a plurality of RATs. When configuredto operate on one or more serving cells where at least one serving cellcorrespond to a first RAT and at least a second serving cell correspondsto a second RAT, the multi-mode WTRU may perform downlink and/or uplinktransmissions using different RATs on different frequencies.

The uplink control information (UCI) in the embodiments described ingreater detail hereafter may comprise at least HARQ A/N, channel stateinformation components such as channel quality indicator (CQI),precoding matrix information (PMI), rank indication (RI), pre-codingcontrol indication (PCI), a scheduling request (SR), an E-DCH transportformat combination indicator (E-TFCI), a happy bit indicator, or aretransmission sequence number (RSN). An SR may be multiplexed with anHARQ A/N pertaining to the second RAT when the resulting UCI (includingthe SR) is transmitted over an uplink channel of the first RAT. Forexample, an SR and at least one HARQ A/N bit(s) pertaining to at leastone downlink HSPA transmission(s) may be multiplexed together fortransmission over, for example, an LTE PUCCH or PUSCH transmission. AnE-TFCI, a happy bit indication and/or an RSN may be multiplexed with atleast one bit of LTE UCI for an uplink transmission, either on an LTEPUCCH or PUSCH transmission or on an E-DPCCH transmission.

Embodiments described hereinafter may be applied alone or in anycombination thereof. The embodiments may be applied to any configurationof multi-RAT operations. The embodiments may be applied to the casewhere the WTRU transmits using different RATs in same or different timeintervals (e.g., time division operation on a transmission time interval(TTI) basis) on different frequencies, or the case where suchtransmissions are performed in the same frequency band.

Embodiments for physical layer procedures for transmitting UCI from oneRAT over another RAT are disclosed hereafter.

In one embodiment, at least part of UCI corresponding to a componentcarrier of a second RAT may be transmitted on a component carrier of afirst RAT, or vice versa. For example, for a WTRU operating in multipleRATs, an uplink control channel for UCI, (e.g., HARQ A/N, CQI, PMI, RI,PCI, etc.), may not be available for the second RAT, (e.g., no uplinkresources are configured, no or insufficient uplink resources areallocated, no uplink resources are activated, or for any other reasonsthat may prevent the WTRU from performing transmissions on the controlchannel, such as insufficient available transmission power, invalidtiming alignment, invalid pathloss reference, or radio link failuredetected). In such cases, the WTRU may transmit at least part of the UCIcorresponding to the second RAT on the uplink resources of the firstRAT. Alternatively, the WTRU may be configured to transmit at least partof the UCI corresponding to the second RAT on uplink resources of thefirst RAT regardless of the availability of the uplink control channelfor UCI on the second RAT.

The WTRU may be configured to use uplink resources of the first RAT totransmit at least part of the UCI corresponding to the second RAT. Forexample, the first RAT may be LTE and the second RAT may be WCDMA orHSDPA (or HSUPA), or vice versa. The uplink resources of the first RAT(if the first RAT is LTE) may use any LTE PUCCH format (e.g., LTE PUCCHformat 1 a, 1 b, 2, 2 a, 2 b, or 3). A set of uplink resources of thefirst RAT may be used for channel selection on these resources, (e.g.,HARQ A/N status is indicated by selecting one of the assigned uplinkresources in addition to setting the HARQ A/N bits). The uplinkresources for the feedback channel for the UCI on the first RAT may be aPUSCH, for example, in the PCell of the WTRU's LTE configuration. Atleast part of the UCI may be transmitted on a first uplink resource ofthe first RAT, and another part of the UCI may be transmitted on asecond uplink resource of the first RAT. For example, the WTRU maytransmit HARQ A/N bits on a PUCCH resource and CQI/PMI/RI bits on aPUSCH resource (either on the PCell or SCell).

The WTRU may prioritize a particular UCI over another in accordance witha priority rule. The UCI with a lower priority may be dropped and maynot be transmitted.

The prioritization may be based on whether or not the UCI pertains tothe primary RAT. For example, at least part of the UCI pertaining to theprimary RAT may be given a higher priority than the UCI pertaining tothe secondary RAT. Alternatively, at least part of the UCI pertaining tothe secondary RAT may be given a higher priority than the UCI pertainingto the primary RAT. In another example, at least part of the UCIpertaining to LTE carriers and/or transmissions may have a higherpriority over HSPA carriers or transmissions, or vice versa.

Alternatively, the prioritization may be based on whether or not the UCIpertains to a primary serving cell or to a secondary serving cell. Forexample, at least part of the UCI pertaining to a primary serving cellmay have a higher priority than the UCI pertaining to a secondaryserving cell. In combination with the rule above, at least part of theUCI of the primary cell of the primary RAT may have a higher prioritythan the UCI of other serving cells of the WTRU.

Alternatively, the prioritization may be based on configuration receivedfrom the network, (e.g., using RRC). For example, the WTRU may beconfigured such that the UCI for a particular type of signal may beprioritized over the UCI for another type of signal.

Alternatively, the prioritization may be based on the mode and/or typeof UCI. For example, a WTRU may prioritize HARQ A/N and SR informationover other types of UCI (e.g., CSI), and additionally, the WTRU mayprioritize between CSI pertaining to different signals based on the typeor mode of the CSI.

Alternatively, for UCI that is reported periodically, the prioritizationmay be based on the periodicity of reporting. For example, if CQIpertaining to the primary RAT and the secondary RAT are reportedperiodically and collide for the same uplink transmission (e.g., in thesame subframe), the CQI reported with the larger periodicity may have ahigher priority.

Alternatively, the prioritization may be based on what subframe withinthe radio frame the WTRU transmits the UCI, or what subframe within theradio frame the WTRU report the UCI for. The subframe pattern may beconfigured by higher layers, (e.g., RRC).

The WTRU may give an absolute priority to the transmission of UCI forthe primary RAT.

Alternatively, the WTRU may give an absolute priority to thetransmission of HARQ A/N information and/or SR. The WTRU may thenprioritize the other UCI (e.g., CSI or CQI/PCI) of the primary RAT overthe secondary RAT. Since transmissions on the secondary RAT may beperformed using radio resources of a largely idle serving cell, the UCIfor the primary RAT may be prioritized.

Alternatively, the WTRU may give an absolute priority to thetransmission of HARQ A/N information and/or SR, and then prioritize theother UCI (e.g., CSI or CQI/PCI) of the secondary RAT over the primaryRAT. Since mobility decisions (e.g., serving cells change) may be basedon the channel quality of the primary RAT, one or more serving cells ofthe secondary RAT may be out of coverage or in bad channel conditions atany time. Moreover, because a WTRU may not be either configured orscheduled with UL transmissions on the secondary RAT, the network (e.g.,an eNB or a NB) may not be aware of the channel conditions, the lack ofcoverage, or measurements performed by the WTRU. Therefore, prioritizingthe UCI for the secondary RAT over the primary RAT may help the networkin subsequent scheduling decisions (e.g., transmission power settingsfor downlink transmissions, beamforming, etc.), and monitoring the radiolink or reconfiguration of the WTRU.

Alternatively, when the number of bits required to acknowledge the datareceived over the configured RATs exceeds the number of information bitsthat may be accommodated using a particular resource(s) dedicated forHARQ ACK/NACK, the WTRU may de-prioritize the transmission of the otherUCI (e.g., CSI/CQI/PCI, etc.) and use the resources/slots assigned forthe other UCI feedback to transmit the HARQ ACK/NACK bits.

Embodiments for multiplexing different types of LTE UCI and HSPA UCI(including SR) are disclosed hereafter. The multiplexed LTE UCI and HSPAUCI may be transmitted over either at least one LTE control channel(PUCCH or PUSCH, hereafter collectively PUxCH) or at least one HSPAcontrol channel (e.g., DPCCH, HS-DPCCH, or E-DPCCH).

The embodiments described described in greater detail hereafter areapplicable for any methods by which the WTRU perform joint encodingeither according to the conventional methods such as methods specifiedfor LTE R10 with carrier aggregation or for 4C-HSPA or for 8C-HSPA, oralternatively any other method that may be defined specifically forjoint encoding in the context of UCI transmission for multi-RAToperation.

FIG. 2 is a flow diagram of an example process for multiplexing the LTEUCI and the HSPA UCI in accordance with one embodiment. A WTRUdetermines what UCI and for which serving cell it needs to transmit(e.g., the type of UCI) for each serving cell of the RATs, and may alsodetermine the number of information bits for each type of UCI (202). TheWTRU may apply UCI priority rules described above to match the number ofbits that may be transmitted in a given uplink transmission on the givenuplink feedback channel in a given subframe.

The WTRU may determine the number of UCI bits for each type of UCI forwhich at least one information bit is to be signaled by the uplinktransmission based on at least one of the following: the number ofconcerned serving cell(s) which may be one of the number of configuredserving cells of the WTRU's multi-RAT configuration or the number ofactive cells of the WTRU's multi-RAT configuration, the number ofserving cells for which UCI is reported in this subframe, thetransmission modes for each configured serving cells, configuration byhigher layer signaling, (e.g., by RRC), whether or not SR is pending,the transmission time of the subframe, or whether or not UCI informationbits may be spread across a plurality of uplink transmissions and, ifso, how many transmissions may be used for the UCI transmission. Theconfigured serving cells for the multi-mode WTRU include the primary andsecondary cells on the primary RAT and either the primary and secondarycells on the secondary RAT if any is configured as such for thesecondary RAT, or the configured serving cells of the secondary RAT.

Referring again to FIG. 2, once the WTRU has determined what UCIinformation may be included in the uplink transmission for a givensubframe, the WTRU generates UCI bits for a serving cell(s) of the RATs(204), and may order the generated UCI bits for the serving cell(s) inaccordance with a predetermined ordering rule (206). The order may bedetermined based on at least one of the following: the type of RATcarrying the uplink feedback transmission, the type of RAT of theserving cell for which the UCI bits pertain to, the type of the servingcell for which the UCI bits pertain to, the serving cell identifierassigned to a serving cell for which the UCI bits pertain to, and/orconfiguration order of the serving cells for which the UCI bits pertainto, etc. The order may be determined per type of UCI (e.g., appliedseparately to HARQ A/N bits and to CSI bits).

With respect to the type of RAT carrying the uplink feedbacktransmission, for example, in case LTE PUxCH is used, one or more SR bitmay be included such that it is ordered to be either first, last, or ata predetermined position in the set of information bits to be encoded ortransmitted.

With respect to the type of RAT of the serving cell for which the UCIbits pertain to, for example, UCI of a primary RAT may be ordered withinthe sequence of information bits before UCI of a secondary RAT. The UCIof the primary RAT and the UCI of the secondary RAT may be orderedwithin the UCI information bits of the primary and secondary RAT,respectively, according to rules described described in greater detailhereafter.

With respect to the type of the serving cell for which the UCI bitspertain to, for example, UCI of one or more primary cells may be orderedbefore UCI of other serving cells.

With respect to the serving cell identifier assigned to a serving cellfor which the UCI bits pertain to, UCI of different serving cells may beordered based on, for example, increasing or decreasing value of theirserving cell identifiers. The order of the cells may be configured byRRC either implicitly, for example, for a primary cell, (e.g., based onordering of corresponding information element in the configurationsequence), and/or explicitly by serving cell identities, (e.g., forsecondary cells, or serving cells of a specific RAT). The serving cellidentities may be applicable to configured serving cells (per-WTRUnumbering space) in which case the order may be in increasing ordecreasing cell identifier value. The serving cell identifiers may beapplicable to configured secondary cells (per SCell numbering space) inwhich case the order may be such that information for the primarycell(s) comes first followed by information for SCells in increasing ordecreasing cell identifier value. The serving cell identifiers may beapplicable to configured serving cells per configured RAT (per RATnumbering space) in which case the order may be such that informationfor the primary RAT comes first followed by information for thesecondary RAT, where information for each RAT is ordered according toany of the previous alternatives.

With respect to configuration order of the serving cells for which theUCI bits pertain to, (i.e., the order in which the serving cells areconfigured for each RAT), for example, the order may be based on thesequence of each serving cell's respective information element within anRRC message that (re)configures the WTRU for multi-RAT operation. It maybe applied for secondary serving cells of the WTRU's configuration.

For example, in ordering the UCI bits, SR bit(s) may be first, followedby HARQ A/N bits (ordered in an increasing or decreasing order ofserving cells), and then followed by the remaining UCI information bits.For example, a WTRU may put SR bit(s) first, followed by HARQ A/N bitsin an increasing or decreasing order of LTE serving cells, and thenfollowed by HARQ A/N bits in an increasing or decreasing order of HSPAserving cells. Alternatively, the WTRU may put the SR bit(s) first,followed by UCI bits for the applicable serving cell(s) ordered inincreasing (or alternatively decreasing) order of their serving cellidentities. Alternatively, the WTRU may order the bits such that an SRis put first followed by UCI bits for the applicable LTE serving cell(s)ordered in increasing (alternatively decreasing) order of their servingcell identities, followed by UCI bits for the applicable HSPA servingcell(s) ordered in increasing (alternatively decreasing) configurationorder.

Referring again to FIG. 2, once the WTRU determines the order of the UCIinformation, the UCI bits are then encoded (208), and the encoded UCIbits are then transmitted on one or more component carriers of one ormore RATs (210).

In one embodiment, the UCI bits of the first RAT and the UCI bits of thesecond RAT may be first concatenated, and then jointly encoded beforetransmission. The WTRU may first concatenate the UCI bits of the firstRAT (e.g., LTE UCI) and the UCI bits of the second RAT (e.g., HSPA UCI),and then jointly encode the concatenated bits before transmission over afeedback channel.

Encoding of the UCI bits may be performed on one or more subset of theordered bits that may be performed per UCI type (e.g., HARQ A/N only,CSI only, or both). For example, the ordered UCI bits for the concernedserving cells may be first concatenated and then jointly encoded fortransmission. Alternatively, the ordered UCI bits for the concernedserving cells of a given RAT may be first concatenated and then jointlyencoded for transmission over different resources (in space, frequency,code or time).

The UCI bits may be first grouped for a pair of concerned serving cellsof the same type, and then the bits for each group may be jointlyencoded and the resulting codewords may be concatenated in time fortransmission. For example, HARQ A/N bits of a pair of serving cells maybe paired for encoding into a composite HARQ A/N. In case there is anodd number of serving cell(s) for a given composite HARQ A/N, the secondbit may be set to discontinuous transmission (DTX). This may beperformed in case of transmission over at least one HSPA uplink channel.

In another embodiment, UCI bits of a first RAT and UCI bits of a secondRAT may be first jointly encoded per subset of serving cells and thenthe resulting bits for each group may be concatenated beforetransmission. Encoding of the UCI information may be performed based onone or more subset of the ordered bits that may be applied per UCI type(e.g., HARQ A/N only, CSI only, or both). The ordered UCI bits may befirst grouped for a pair of concerned serving cells, and then the bitsfor each group may be jointly encoded and the resulting codewords may beconcatenated in time.

For example, for HARQ feedback, the encoding for the composite HARQ A/Nmay be performed based on the conventional multi-cell HSPA rules (e.g.,4C-HSDPA), wherein a composite HARQ A/N is created per group of servingcells. Each composite HARQ A/N comprises jointly encoded bits for thegroup of serving cells. The composite HARQ A/N for each group of servingcells is concatenated and may be transmitted over a feedback channel,(e.g., the HS-DPCCH). The group may include two serving cells that maybe configured to transmit with or without MIMO. The serving cells maycomprise serving cells over multiple RATs. The order in which they aregrouped and then concatenated is explained in greater detail hereafter.This may be performed in case of transmission over at least one HSPAuplink channel.

For example, HARQ A/N bits may be ordered in configuration sequence ofthe concerned serving cells and a composite HARQ A/N bits may begenerated by pairing bits two-by-two in sequence. If the WTRU uses anHSPA uplink channel for HARQ A/N transmission, the WTRU may first orderthe HARQ A/N bits, for example, in accordance with the sequence ofconfiguration of the serving cells, and then determine a composite HARQA/N pair by grouping bits two-by-two in sequence, and each compositeHARQ A/N may be jointly encoded using the applicable codeword. The WTRUmay then concatenate the resulting codewords for transmission over theHSPA uplink channel. In case there is an odd number of serving cell(s)for a given composite HARQ A/N, the second bit may be set to DTX. HARQA/N bits for the cells may first be grouped per RAT before the WTRUdetermines the composite HARQ A/N pair(s). This may be performed in caseof transmission over at least one HSPA uplink channel.

For another example, CSI bits may be ordered in configuration sequenceof the concerned serving cells (e.g., in accordance with the orderingrules disclosed above), and composite CSI may be generated by pairingthe CSI bits two-by-two, (e.g., pairing in alternating order such aspairing CSI for cells 1 and 3, and paring CSI for cells 2 and 4, and soon, or alternatively paring first two cells and the next two cells, andso on). If a WTRU uses an HSPA uplink channel for CSI transmission, theWTRU may first order the CSI bits, for example, in accordance with thesequence of configuration of the serving cells, and CSI bit(s) may bepaired two-by-two to form composite CSI, and the composite CSI may bejointly encoded and transmitted over the HSPA uplink channel in atime-division manner (e.g., a first composite CSI in a first TTI and asecond composite CSI in the following TTI).

The WTRU may apply this method to one (or a subset of) type of UCI, suchas the HARQ A/N information pertaining to downlink reception for LTEand/or HSPA, or to the CSI for at least one serving cell for LTE and/orHSPA. Once the UCI is encoded according to any of the embodimentsdescribed heretofor, the WTRU may transmit the resulting encodedinformation over an uplink feedback channel, such as PUxCH or HS-DPCCHor any other channel used to carry uplink feedback.

In another embodiment, UCI bits of a first RAT and UCI bits of a secondRAT may be separately encoded and then concatenated before transmissionover the uplink channel. The respective encoding (e.g., coding rates)may be performed such that each set of bits may meet a target errorperformance, for example, by ensuring that a similar transmission powermay be achieved for each set of bits. The transmission of the differentset of encoded bits may be performed on different resource locations onat least one uplink carrier used for transmission of uplink controlinformation. For example, LTE UCI and HSPA UCI bits may be firstseparately encoded and then concatenated before transmission over aPUxCH. The respective coding rates and/or schemes applied to each of LTEand HSPA UCI bits may be adjusted in a way that results in the sametransmission power for achieving the respective target errorperformance. For example, in case the HSPA UCI comprises a singleinformation bit which is repeated over two LTE subframes, a highercoding rate may be utilized for this bit (such as no channel coding or asimple repetition) than for the LTE UCI bits.

LTE HARQ A/N information and/or HSPA HARQ A/N information applicable tomore than one codeword may be bundled together to reduce the number ofHARQ A/N information bits to transmit. For instance, a single bit may betransmitted to represent either a HARQ ACK or HARQ NACK for a bundle ofcodewords, where HARQ ACK is transmitted if all codewords of the bundlewere received successfully and HARQ NACK is transmitted if at least onecodeword of the bundle is not received successfully. The bundling may beapplied to HARQ A/N information across codewords per carrier (or servingcell) for all or subsets of carriers. Alternatively, the bundling may beapplied to codewords received across a predetermined set of carriers (orserving cells) or a subset thereof. Alternatively, the bundling may beapplied to codewords received across a set of subframes, for instanceconsecutive LTE subframes of 1 ms. This may be useful in case theinformation needs to be transmitted over a single HSPA subframe of 2 ms,considering the limited capacity of an HS-DPCCH for the transmission ofLTE UCI (along with the transmission of HSPA UCI). Alternatively, thebundling may be applied to HARQ A/N information pertaining to transportblocks received in a plurality of HSPA and/or LTE DL component carriers(the timing may be specified similarly as described in otherembodiments). The bundling may be performed by AND operation over bitsor summing the bits together (such as counting the number of ACKs) andmodulo a certain value.

Embodiments for transmission of UCI pertaining to HSPA signals (HSPAUCI) over at least one LTE uplink physical channel such as PUCCH orPUSCH (collectively PUxCH) are explained in greater detail hereafter.Unless otherwise specified, the following embodiments apply totransmission over any of these channels. An HSPA signal may refer to atransmission over the HS-SCCH and/or the HS-PDSCH (at the physicallayer). It may refer to a transmission over the HS-DSCH transportchannel. The HSPA UCI may include ACK/NACK to downlink controlinformation (such as HS-SCCH orders), or HARQ ACK/NACK, CSI, PCI, RI.

FIGS. 3 and 4 show frame structures of HSPA and LTE, respectively. InHSPA, each 10 ms radio frame comprises 5 equally sized subframes of 2 msand each subframe comprises 3 time slots. In LTE, each 10 ms radio framecomprises 10 equally sized subframes of 1 ms, (i.e., the TTI for LTE isa 1 ms subframe). Considering that the TTI of the HS-DSCH is 2 ms, whilethe subframe duration of either PUCCH or PUSCH is 1 ms, timingrelationships may be defined between the reception of HSPA signals froma DL CC and the transmission of corresponding UCI over an LTE physicalchannel.

In one embodiment, the HSPA UCI corresponding to a specific HSPA signalmay be transmitted on a PUxCH over a single LTE subframe of 1 ms. Inthis case, such transmission may occur in subframe N+k, where k is aparameter of either fixed value or a value provided by higher layers,and N is the reference subframe of the HSPA signal in the LTE subframenumbering. The reference subframe N and the parameter k are described ingreater detail hereafter.

In another embodiment, the HSPA UCI corresponding to a specific HSPAsignal may be transmitted on a PUxCH over two LTE subframes of 1 ms, forexample, in subframes N+k and N+k+1.

The reference subframe N may correspond to one of the subframe duringwhich (or at the start of which) the HS-SCCH transmission starts, thesubframe during which (or at the start of which) the HS-PDSCHtransmission starts, the subframe during which (or at the start ofwhich) the HS-DSCH transmission starts, the subframe during which (or atthe end of which) the HS-SCCH transmission ends, the subframe duringwhich the HS-DPSCH transmission ends, or the second subframe overlappingwith at least one of the HS-SCCH, HS-PDSCH or HS-DSCH. Alternatively,the subframe N may be the first subframe at which starting boundary atleast one of the HS-SCCH, HS-PDSCH and HS-DSCH transmission is ongoing.

For a transmission in a serving cell configured for LTE operation (LTEfrequency division duplex (FDD) or time division duplex (TDD)), thevalue of k may be set to a fixed value of four (4) subframes. For LTETDD, the value of k may correspond to the value of the HARQ timing forTDD.

In case the HSPA UCI is transmitted over a plurality of LTE subframes,the WTRU may repeat the UCI in each transmission, using one of the abovetiming relationships. Alternatively, the WTRU may send a subset of UCIin each transmission (e.g., a first subset in transmission at N+k, asecond subset at N+k+1) using the above timing relationships for thereception of the concerned downlink transmissions (e.g., based on thereference subframe N). Either subset may be empty.

The UCI transmitted in the two subframes may be partitioned and encodedbased on at least one of the following: the type of UCI, the carriers towhich the UCI pertains, the codeword (or the transport block), a fixedtarget number of UCI bits per transmission, reception of explicitcontrol signaling, encoding of the UCI, or higher layer configuration.

For example, the HARQ A/N may be transmitted in one subframe and CSI maybe transmitted in the second subframe). In case there are at least twocarriers configured for HSPA, the UCI pertaining to a first carrier or afirst group of carriers may be transmitted in a first subframe and theUCI pertaining to a second carrier or a second group of carriers may betransmitted in a second subframe.

In case the UCI comprises at least HARQ A/N information for more thanone HSPA codeword (or transport block), a subset of HARQ A/N informationfor a first subset of codewords may be transmitted in a first subframeand a subset of HARQ A/N information for a second subset may betransmitted in a second subframe. For instance, in case HARQ feedback isfor two HSPA codewords transmitted from a single carrier, the feedbackfor the first and second codewords may be transmitted on the first andsecond subframes, respectively.

The WTRU may determine how to partition and/or encode the HSPA UCIconsidering the amount of UCI to be transmitted over LTE in eachsubframe. For example, the number of information bits for HARQ A/N ofHSPA in each subframe may be set in a way that result in an equal totalnumber of HARQ A/N bits to be transmitted in each subframe. Since theTTI in HSPA is 2 ms and the TTI in LTE is 1 ms, if the HSPA UCI istransmitted over LTE, the HSPA UCI may be split and spread over twosubframes so that equal number of bits of the LTE and HSPA UCI bits maybe transmitted in each subframe.

Reception of explicit control signaling may be used as a basis forpartitioning the UCI. The control signaling may be derived from acharacteristic of, or indication from, at least one control channel(such as HS-SCCH or PDCCH) used for scheduling of at least one codewordtransmitted in HSPA carrier and/or LTE carrier. For example, a WTRU maytransmit HARQ A/N information pertaining to the transmission of HSPAcodewords in either subframe N+k or N+k+1 depending on an indication(field) decoded from the HS-SCCH used for scheduling said HSPAcodewords.

Alternatively, a WTRU may transmit HARQ A/N information either insubframe N+k or N+k+1 depending on which one of specific configuredHS-SCCH was used for the scheduling.

Alternatively, a WTRU may transmit HARQ A/N information pertaining toHSPA codeword(s) either in subframe N+k or N+k+1 depending on anindication (or the existence thereof) received in a PDCCH used forscheduling of LTE codewords in subframes N or N+1, respectively.

Alternatively, a WTRU may transmit HARQ A/N information pertaining toHSPA either in subframe N+k or N+k+1, depending on the TTI in whichHS-SCCH was received. For example, if the HS-SCCH was received in an oddTTI then the WTRU may use N+k otherwise the WTRU may use N+k+1.

Using any of the examples above may allow the network to dynamicallycontrol which of a plurality of subframes may be used to transmit HSPAfeedback.

The WTRU may apply different coding rates and/or schemes to thedifferent UCI subsets in order to achieve the respective target errorrates at the same transmission power. Information about the subset ofUCI information to be transmitted in each subframe (for instance, thenumber of bits in each subframe) may be provided by higher layers.

With the schemes disclosed above, the transmission of UCI, in particularHARQ A/N for HSPA, may be performed by spreading in time thetransmission of the information.

With respect to the selection of PUCCH or PUSCH for transmission of theHSPA UCI, the following embodiments may be used.

In one embodiment, the HSPA UCI may be transmitted on a PUCCH. Thisembodiment may be applied if the possibility of simultaneous PUCCH andPUSCH transmission is configured by higher layers.

In another embodiment, the HSPA UCI may be transmitted on a PUS CH Thisembodiment may be applied when an uplink assignment is available(otherwise either the HSPA UCI is transmitted on a PUCCH resource or itis not transmitted). This embodiment may be applied if the possibilityof simultaneous PUCCH and PUS CH transmission is configured by higherlayers, or if LTE UCI is transmitted on a PUCCH transmission, (e.g.,HSPA UCI may be transmitted on a PUSCH resource when LTE UCI istransmitted on a PUSCH).

In another embodiment, the HSPA UCI may be transmitted over the samesingle physical channel and the same UL CC as the LTE UCI, according torules applicable to the selection of physical uplink channel for thetransmission of LTE UCI.

In another embodiment, a first part of the HSPA UCI may be transmittedin a first PUxCH and a second part of the HSPA UCI may be transmitted ina second PUxCH. For instance, the HARQ A/N part of HSPA UCI may betransmitted on the PUCCH while the CSI part of the HSPA UCI may betransmitted on the PUSCH.

Embodiments for transmission of HSPA UCI over a PUCCH are disclosedhereafter. The PUCCH may be of any format, such format 1 a/b, format 2,or format 3. Hereafter, the term “corresponding PDCCH/PDSCHtransmission” may refer to a PDCCH/PDSCH transmission for which thecorresponding UCI (e.g., HARQ A/N) is transmitted in the concernedsubframe, and the term “corresponding HS-SCCH transmission” may refer toan HS-SCCH or HS-DPSCH transmission for which the corresponding UCI(e.g., A/N or HARQ A/N) is transmitted in the concerned subframe.

The PUCCH resource used to transmit the HSPA UCI (and the LTE UCI) maybe obtained according to at least one of the following methods.

In one embodiment, the PUCCH resource index may be received from thecorresponding HS-SCCH transmission. This may be the case if nocorresponding PDSCH transmission (or no corresponding PDSCH transmissionfor a secondary LTE serving cell) is received. The resource index may beeither indicated explicitly in the received HS-SCCH, or derivedimplicitly based on which one of the configured HS-SCCHs was used forthe transmission. For instance, if the WTRU is configured to receive theHS-DSCH using one out of four configured HS-SCCHs, the identity of thespecific HS-SCCH that is used for a given HSPA transmission may be usedin the determination of the PUCCH resource index. In case of anHS-SCCH-less transmission, the PUCCH resource index may be determinedfrom a value configured by a higher layer. Alternatively, the specificcombination of HS-SCCHs used for HSPA transmissions in multiple carriersmay be used in deriving the PUCCH resource index. Alternatively, theTTI, the frame number, or the subframe number in which the HS-SCCH wasreceived may be used in determining the PUCCH resource index.

In another embodiment, the PUCCH resource index may be received from thePDCCH of the corresponding LTE transmission. The index may be indicatedexplicitly from a field of the PDCCH, or be derived from anotherproperty of the PDCCH such as the position of its first control channelelement. This may be the case if the corresponding PDSCH transmissionfor a secondary LTE serving cell is received. Alternatively, if thecorresponding PDSCH transmission does not exist, the resource index maybe obtained from a PDCCH encoded with a special format and indicatingthe transmission of one or more HSPA signal(s) from the HSPA DLcomponent carrier(s). Alternatively, the resource index may be obtainedfrom a PDCCH encoded with a format used to indicate the PUCCH resourceindex for the transmission of HSPA feedback associated with thesimultaneous or concurrent HSPA transmissions scheduled over the HS-SCCHor received of the HS-PDSCH.

In another embodiment, the PUCCH resource index may be provided by ahigher layer. This may be used in case no resource index may be signaledfrom either a PDCCH or HS-SCCH transmission.

In another embodiment, the PUCCH resource to use may be the same as thePUCCH resource used in the immediately preceding subframe. Thisembodiment may be used for the subframe N+k+1 in case where the HSPA UCIis transmitted over two subframes (N+k and N+k+1).

In another embodiment, the PUCCH resource used by the WTRU may be thesame as the PUCCH resource used for the previous transmission of UCI, inany of the previous subframes. This may be used in case where noresource index is received from either a PDCCH or HS-SCCH transmission.

The coded bits of UCI information pertaining to HSPA and/or LTE carriersmay be multiplexed over format 3 of PUCCH. In case the UCI is jointlyencoded, the coded bits may be multiplexed using the same method usedfor the transmission of the UCI of LTE carriers. In case the UCI of HSPAand LTE carriers are separately encoded with different coding rates, theencoding may be such that the sum of coded bits may be equal to fortyeight (48). Each coded bit may be spread over a number of symbols Non acertain time slot and sub-carrier. The number of symbols N on the secondslot of the subframe may depend on whether a shortened PUCCH format isused (e.g., in case SRS is transmitted in the last symbol of thesubframe).

In selecting the time slots and sub-carriers over which the UCI bitspertaining to an HSPA carrier or an LTE carrier are transmitted, thetime slot with the lesser number of symbols N may be selected for codedbits encoded with the higher code rate. This may allow for balancing theerror performance in case the two time slots do not have the same numberof symbols. Alternatively, one time slot may be selected for onefraction of the coded bits that have been encoded for either HSPA or LTEUCI, and the second time slot may be selected for the remaining codedbits encoded for the HSPA or LTE, wherein the fraction may be one half.This method utilizes time diversity within coded bits. Alternatively,within a certain time slot, a subset of sub-carriers separated by unitsof 12/M may be selected for coded bits that have been encoded for eitherHSPA or LTE UCI, where M is the number of such coded bits that aremapped to this time slot. This may utilize frequency diversity withincoded bits. Alternatively, different subsets of sub-carriers may beselected between the two time slots for coded bits that have beenencoded for either HSPA or LTE UCI.

UCI information pertaining to HSPA and/or LTE carriers may bemultiplexed over PUCCH format 2. HARQ A/N bits pertaining to an HSPA DLcarrier transmission, or bits obtained from bundling between HARQ A/Nbits pertaining to both HSPA and LTE DL carrier transmissions may bemultiplexed with CSI information of at least one HSPA DL carrier or LTEDL carrier using the same method as for the multiplexing of HARQ A/N andCSI bits over PUCCH format 2 a or 2 b for an LTE carrier.

UCI information pertaining to HSPA and/or LTE carriers may bemultiplexed over PUCCH format 1/1 a/1 b.

In one embodiment, in case of aggregating one HSPA DL carrier with oneLTE DL carrier, up to two HARQ A/N bits pertaining to the HSPA DLtransmission in at least one sub-frame and up to two HARQ A/N bitspertaining to the LTE DL transmission in at least one sub-frame may becombined to select a PUCCH format 1 b resource and a modulation symbolaccording to a channel selection codebook.

In another embodiment, in case of aggregating at least one HSPA DLcarrier with at least one LTE DL carrier, a positive SR may be signaledalong with HARQ A/N information pertaining to at least one HSPA DLand/or at least one LTE DL transmission. This may comprise firstbundling HARQ A/N bits pertaining to these transmissions, and thenmodulating a PUCCH signal of format 1/1 a/1 b based on the outcome ofthe bundling operation (such as mapping to a constellation point). ThePUCCH resource may be obtained from a higher layer or assigneddynamically.

UCI pertaining to LTE signals (LTE UCI) from at least one carrier may betransmitted over at least one HSPA uplink physical channel such as theHS-DPCCH, the E-DPCCH, or the DPCCH. Embodiments described hereafter mayapply to transmission over any of these channels, which may becollectively referred to as “HSPA uplink physical channel.” An LTEsignal may refer to the reception by the WTRU of a transmission over thePDCCH channel and/or the PDSCH channel (at the physical layer). It mayrefer to the reception by the WTRU of a transmission over the DL-SCHtransport channel.

The UCI feedback for LTE and/or HSPA signals may be sent over theHS-PDCCH using slot format 0 or slot format 1. Alternatively, a new slotformat may be used to allow more information bits to be transmitted overthe HS-DPCCH, wherein a new spreading factor, (e.g., 64), may be used.

The slot format and channel coding may be determined based on at leastone of the following: total number of serving cells configured acrossall RATs or activated serving cells, the configured transmission modefor each concerned serving cell, whether or not at least one servingcell is configured for a secondary RAT, the number of cells configured(or active) for the secondary RAT, or explicit configuration by thenetwork.

Embodiments for multiplexing the coded bits of UCI informationpertaining to HSPA and/or LTE carriers over an HSPA feedback channel aredisclosed in greater detail hereafter.

In one embodiment, an HARQ-ACK message may be created per group ofserving cells across all configured RATs. An HARQ-ACK message (orcomposite HARQ-ACK or codeword) may be formed by jointly encoding theHARQ-ACK states for each serving cells belonging to the group(configured with or without MIMO). The group may comprise a pair ofserving cells that belong to the same RAT or to different RATs.

Each group and logical association of the serving cells to the HARQ-ACKmessages may be determined by pairing the primary and secondary servingcells in order. The order of the serving cells across both RATs may bedetermined according to the rules disclosed above. In case there is anodd number of serving cell(s), the given HARQ-ACK message may comprisethe HARQ acknowledgment of a serving cell and a DTX message in thatorder.

The CSI report may be formed according to the following rules. In eachHS-DPCCH subframe the WTRU may be allowed to transmit the CSI of twoserving cells. The CQI or CQI/PCI/RI for each serving cell may beindependently encoded and concatenated to form a composite CSI. Thelogical association of the serving cells to the CSI report may bedetermined by pairing odd and even serving cells across the RATs inorder as described herein.

A CSI report may be encoded individually per cell and transmittedindividually per cell. This may be used if the LTE CSI report requiresmore bits than an HSPA CSI report requires. An LTE CSI report may betransmitted individually in an HS-DPCCH subframe, but the HSPA feedbackmay be transmitted in pairs. In each HS-DPCCH subframe the WTRU may beallowed to transmit CSI of up to four cells, (e.g., if a new HS-DPCCHslot format is introduced).

In one embodiment, the UCI feedback over an HSPA channels may betransmitted using the HS-DPCCH slot format 0 (i.e., spreading factor256) or slot format 1 (i.e., spreading factor 128). A slot format 0 maybe used, for example, when the WTRU is configured with one HSPA servingcell and one LTE serving cell. Alternatively, the slot format 0 and theassociated coding for three cells may be used when a total of threeserving cells without MIMO are configured across all RATs. Otherwise,the WTRU may use the HS-DPCCH slot format 1 to transmit the feedback.

For example, the HARQ-ACK messages may be concatenated and transmittedin the first slot, and the CSI reports may be transmitted in the secondand third slot of the HS-DPCCH. Given that the WTRU may transmit up totwo CSI reports in an HS-DPCCH sub-frame, the reporting for differentpairs of serving cells may be transmitted in different sub-frames, whichmay or may not be consecutive. The cycle or periodicity of the CSImessages may be independently configured for each group. Alternatively,one cycle may be configured. In this case, the WTRU may transmit the CSIfeedback of each group in order in consecutive sub-frames orconsecutively in group order in predetermined sub-frames.

The power used for each composite HARQ-ACK may be determined andadjusted to result in the same transmission power for achieving therespective target error performance. The offsets for ACK, NACK, and/orCQI may be separately configured for each target RAT.

Alternatively, the HARQ-ACK information may be transmitted in one ormore slots of the HS-DPCCH. If the number of bits to transmit theHARQ-ACK for the configured cells is greater than the number of bitsthat may be acknowledged with an HS-DPCCH slot format, the WTRU may usethe slots reserved for CQI/PCI reporting (e.g., slot 2 and/or slot 3).The coding of the information for slot 2 or 3 may follow the same rulesas the coding for slot 1. The group of HARQ-ACK that is transmitted overslot 2 or 3 may correspond to the group of serving cells in the order ofconfiguration. Alternatively, a different rule may be defined whereinthe HSPA HARQ-ACKs are grouped, coded, and concatenated on the firstslot or a predefined slot, and the LTE HARQ-ACKs are grouped, coded, andconcatenated on a second or predefined slot of the HS-DPCCH. In thisembodiment, the HARQ-ACK may have priority over the CSI feedback.

The WTRU may transmit over one or more slots of the HS-DPCCH. If theWTRU detects an HS-SCCH, HS-DPSCH, PDCCH, or PDSCH transmissionaddressed to the WTRU, the WTRU may use the new HS-DPCCH to transmitHARQ-ACK and may not include the CSI information. Otherwise, the WTRUmay send the CSI information using the normal coding if triggered on thecorresponding TTI. If one RAT transmitted, the WTRU may use the firstslot. Otherwise, the WTRU may use more than one slot of the HS-DPCCH.

The set of sub-frames in which the WTRU uses the normal HS-DPCCH slotsfor CSI feedback or vice versa may be preconfigured. A new informationbit or codeword may explicitly indicate to the network that thisHS-DPCCH includes HARQ-ACK information over the full HS-PDCCH and noCSI. For example, the WTRU may use the special codeword or informationto indicate to the network on the first slot that the next two slots areused for HARQ-ACK information. If more than one composite HARQ-ACK istransmitted and configured the WTRU may use the special reserved codeover both composite HARQ-ACKs or over just one of them. Otherwise, ifone slot is used for HARQ-ACK and the other two are used for CSI, theWTRU may use any of the existing codewords or DTX the slot.

In another embodiment, two HS-DPCCH channelization codes may be used totransmit LTE UCI and HSPA UCI. For example, depending on the number ofserving cells configured for each carrier, the feedback for the primaryRAT may be sent on a first HS-DPCCH channelization code and the feedbackfor the secondary RAT may be sent on a second HS-DPCCH channelizationcode. The coding of the bits and the choice of the slot format to usemay depend on the number of serving cells configured and active and thetransmission mode configured for each RAT, as is used for a singleHS-DPCCH. Alternatively, the grouping and encoding of feedback may beperformed in accordance with any of the embodiments described heretofor(e.g., serving cells are paired), and the UCI information of the firstpairs of serving cells may be sent on a first HS-DPCCH and the UCIinformation of the other pairs may be sent over a second HS-DPCCH incase where more than X serving cells across all RATs are configured,where X is the maximum number of serving cells with or without MIMO thatmay be acknowledged in a single HS-DPCCH.

In another embodiment, the E-DPDCH code/slot space may be used totransmit the UCI. For example, the UCI of any of the configured RATs maybe transmitted over the E-DPD CH. Alternatively, the LTE UCI may betransmitted over the E-DPDCH. In this example, the HSPA feedback may beprovided over the HS-DPCCH and the LTE feedback may be provided over theE-DPDCH. Alternatively, the feedback may be provided over an MAC controlelement (CE) or an MAC PDU. Alternatively, the E-DPDCH or the MAC CE maybe used to report aperiodic CSI reports, whereas the HS-DPCCH may beused to transmit the periodic CSI reports.

A WTRU may receive a request for aperiodic CSI reporting for HSPA and/orLTE via an LTE control channel. LTE standards define the functionalityfor aperiodic CSI reporting. In one embodiment, a request for aperiodicCSI reporting may be transmitted over LTE, (i.e., the PDCCH), for atleast one of serving cells. The requested serving cell(s) may correspondto either LTE serving cell(s) or HSPA serving cell(s), or to one or moreserving cells of both HSPA and LTE. This may allow an LTE network torequest a CSI report for any of the serving cells.

In another embodiment, a request for aperiodic CSI report may betransmitted over an HSPA physical channel, such as an HS-SCCH. A newHS-SCCH format or order may be defined and used for aperiodic CSIrequest for LTE and/or HSPA serving cells.

Upon reception of such request, the WTRU may create the report and sendit using one or a combination of the following schemes. The WTRU maytransmit the report over a MAC CE. Alternatively, the WTRU may transmitthe report over an HS-DPCCH, wherein the subframe in which the CSI isreported corresponds to the first subframe in N+k in which the CSI ofthe corresponding serving cell is allowed to be reported, and where N isthe subframe in which the request is received and k is a predefined ornetwork configured value. Alternatively, the subframe that the CSI isreported may be explicitly indicated in the request. Alternatively, theWTRU may transmit the report on the E-DPDCH. The code and space overwhich to transmit the report may be pre-configured, explicitly signaledon the PDCCH or HS-SCCH, or implicitly determined. The aperiodic LTE andHSPA CSI may be appended together and sent over the HSPA uplinkchannel(s) or the LTE channel(s).

Considering that the TTI of the DL-SCH in LTE is 1 ms, while thesubframe duration of an HSPA uplink physical channel such as theHS-DPCCH is 2 ms, timing relationships between the reception of LTEsignals from a DL CC and the transmission of corresponding UCI over anHSPA uplink physical channel are described in greater detail hereafter.

In one embodiment, the LTE UCI, corresponding to LTE signals from twoconsecutive LTE subframes of 1 ms, may be transmitted in a single 2 mssubframe of the HS-DPCCH. For example, the LTE UCI transmitted insubframe N (in the HSPA uplink subframe numbering) may correspond to LTEsignals transmitted at the start or during subframe N−k and N−k+1, wherek is a parameter of either fixed value or a value provided by a higherlayer. Alternatively, the subframe N may be the subframe at whichstarting boundary of the transmission of the LTE signal(s) is ongoing.

Although features and elements are described above in particularcombinations, one of ordinary skill in the art will appreciate that eachfeature or element can be used alone or in any combination with theother features and elements. In addition, the methods described hereinmay be implemented in a computer program, software, or firmwareincorporated in a computer-readable medium for execution by a computeror processor. Examples of computer-readable media include electronicsignals (transmitted over wired or wireless connections) andcomputer-readable storage media. Examples of computer-readable storagemedia include, but are not limited to, a read only memory (ROM), arandom access memory (RAM), a register, cache memory, semiconductormemory devices, magnetic media such as internal hard disks and removabledisks, magneto-optical media, and optical media such as CD-ROM disks,and digital versatile disks (DVDs). A processor in association withsoftware may be used to implement a radio frequency transceiver for usein a WTRU, UE, terminal, base station, RNC, or any host computer.

1. A method for sending uplink control information by a multi-modewireless transmit/receive unit (WTRU) capable of operating on multiplecomponent carriers of a plurality of radio access technologies (RATs)for multi-RAT operation, the method comprising: generating uplinkcontrol information (UCI) pertaining to a first RAT; and sending atleast part of the UCI via a feedback channel on a component carrier of asecond RAT.
 2. The method of claim 1 wherein the UCI includes at leastone of hybrid automatic repeat request acknowledgement (HARQ-ACID, achannel quality indicator (CQI), a precoding matrix indicator (PMI), arank indication (RI), a pre-coding control indication (PCI), ascheduling request (SR), an E-DCH transport format combination indicator(E-TFCI), a happy bit, or a retransmission sequence number (RSN).
 3. Themethod of claim 1 wherein the first RAT is Long Term Evolution (LTE) andthe second RAT is High Speed Packet Access (HSPA), and the feedbackchannel is at least one of a high speed dedicated physical controlchannel (HS-DPCCH), an E-DCH dedicated physical control channel(E-DPCCH), or a dedicated physical control channel (DPCCH).
 4. Themethod of claim 1 wherein the first RAT is High Speed Packet Access(HSPA) and the second RAT is Long Term Evolution (LTE), and the feedbackchannel is at least one of a physical uplink control channel (PUCCH) ora physical uplink shared channel (PUSCH).
 5. The method of claim 4wherein hybrid automatic repeat request (HARQ) acknowledgement feedbackis transmitted on the PUCCH and other UCI is transmitted on the PUSCH.6. The method of claim 1 wherein a particular UCI is prioritized overanother in accordance with a priority rule.
 7. A method for sendinguplink control information by a multi-mode wireless transmit/receiveunit (WTRU) capable of operating on multiple component carriers of aplurality of radio access technologies (RATs), the method comprising:determining a type of uplink control information (UCI) to be transmittedfor each serving cell of a first RAT and a second RAT; generating UCIbits for each serving cell of the first RAT and the second RAT; orderingthe UCI bits in accordance with a predetermined ordering rule; encodingthe ordered UCI bits; and transmitting the encoded UCI bits on at leastone component carrier of at least one of the first RAT or the secondRAT.
 8. The method of claim 7 wherein UCI bits for a pair of servingcells are jointly encoded.
 9. The method of claim 7 wherein the UCI bitsfor the first RAT and the second RAT are concatenated and jointlyencoded.
 10. The method of claim 7 wherein the UCI bits for the firstRAT and the second RAT are separately encoded and concatenated beforetransmission.
 11. A multi-mode wireless transmit/receive unit (WTRU)capable of operating on multiple component carriers of a plurality ofradio access technologies (RATs) for multi-RAT operation, the WTRUcomprising: a processor configured to generate uplink controlinformation (UCI) pertaining to a first RAT and send at least part ofthe UCI via a feedback channel on a component carrier of a second RAT.12. The WTRU of claim 11 wherein the UCI includes at least one of hybridautomatic repeat request acknowledgement (HARQ-ACID, a channel qualityindicator (CQI), a precoding matrix indicator (PMI), a rank indication(RI), a pre-coding control indication (PCI), a scheduling request (SR),an E-DCH transport format combination indicator (E-TFCI), a happy bit,or a retransmission sequence number (RSN).
 13. The WTRU of claim 11wherein the first RAT is Long Term Evolution (LTE) and the second RAT isHigh Speed Packet Access (HSPA), and the feedback channel is at leastone of a high speed dedicated physical control channel (HS-DPCCH), anE-DCH dedicated physical control channel (E-DPCCH), or a dedicatedphysical control channel (DPCCH).
 14. The WTRU of claim 11 wherein thefirst RAT is High Speed Packet Access (HSPA) and the second RAT is LongTerm Evolution (LTE), and the feedback channel is at least one of aphysical uplink control channel (PUCCH) or a physical uplink sharedchannel (PUSCH).
 15. The WTRU of claim 14 wherein the processor isconfigured to transmit hybrid automatic repeat request (HARQ)acknowledgement feedback on the PUCCH and other UCI on the PUSCH. 16.The WTRU of claim 11 wherein the processor is configured to prioritize aparticular UCI over another in accordance with a priority rule.
 17. TheWTRU of claim 11 wherein the processor is configured to determine a typeof UCI to be transmitted for each serving cell of the first RAT and thesecond RAT, generate UCI bits for each serving cell of the first RAT andthe second RAT, order the UCI bits in accordance with a predeterminedordering rule, encode the ordered UCI bits, and transmit the encoded UCIbits on at least one component carrier of at least one of the first RATor the second RAT.
 18. The WTRU of claim 17 wherein the processor isconfigured to encode the UCI bits for a pair of serving cells jointly.19. The WTRU of claim 17 wherein the processor is configured toconcatenate UCI bits for the first RAT and the second RAT and jointlyencode the concatenated UCI bits.
 20. The WTRU of claim 17 wherein theprocessor is configured to separately encode UCI bits for the first RATand the second RAT and concatenate before transmission.